thebookofshaders/07/circle.frag
2015-05-10 18:19:50 -04:00

25 lines
527 B
GLSL

// Author @patriciogv - 2015
// http://patriciogonzalezvivo.com
#ifdef GL_ES
precision mediump float;
#endif
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
float circle(in vec2 _st, in float _radius){
vec2 l = _st-vec2(0.5);
return 1.-smoothstep(_radius-(_radius*0.01),
_radius+(_radius*0.01),
dot(l,l)*4.0);
}
void main(){
vec2 st = gl_FragCoord.xy/u_resolution.xy;
vec3 color = vec3(circle(st,0.9));
gl_FragColor = vec4( color, 1.0 );
}